Capacitive touch sensors are prone to noise, environmental variation, PCB variation and device lot variation. For a multi-touch touch-screen application, a force and sense sensing front-end is required. This front-end measures cross-capacitance in the X-axis and Y-axis of a projected capacitive touch-screen structure. A robust noise filtering technique is also required to reduce the effect of external noise which is easily coupled to the sensor. A calibration system which is able to offset the effect of environmental variation, PCB variation and device lot variation is also required. The capacitive touch sensor system of the present invention provides a novel solution to meet the above-mentioned requirements.